Slotback

Slotback (sometimes referred to as an A-back) is a position in gridiron football. The "slot" is the area between the last offensive lineman on either side of the line of scrimmage and the wide receiver on that side. A player who lines up between those two players and behind the line of scrimmage is a slotback. The position appears primarily in Canadian football, but is also used at times in American football. The slotback is similar to the wide receiver but also has many of the same traits as a running back; a slotback lines up closer to the offensive line and often farther back than a wide receiver.

Slotbacks are often as many as five yards behind the line of scrimmage when the ball is snapped and, in the Canadian game, may also make a running start toward the line of scrimmage prior to the snap. (In American football, this would be an illegal motion.)